Process of making paris-green.



No. 698,696. Patented Apr. '29, |902. B. FRANCHUT.

PROCESS 0F MAKING PARIS GREEN.

\ (Application led Aug. 17, 1901.)

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UNITED STATES PATENT QEEICE.

RICHARD FRANCHOT, OF NIAGARA FALLS, NEV YORK.

PROCESS OF MAKING PARIS-GREEN.

SPECIFICATION forming part of Letters Patent No. 698,696, dated April29, 1902.

Application tiled August 17, 1901- To a/ZZ whom, t may con/cern.-

Be it known that I, RICHARD FRANoHo'r, a citizen of the United States,residing at Niagara Falls, county of Niagara, and'State of New York,have invented certain new and useful Improvements in Processes of MakingParis-Green, fully described and represented in the followingspecification and the accompanying drawing, forming a part of the same.

This invention relates to a process of making paris-green from metalliccopper by electrolysis.

The invention consists, essentially, in sub-v preferably use an anodeconsisting of a thick plate of copper and a cathode which may be only athin sheet of copper, these being immersed in the solution. The cathodeis surrounded by a linen bag as a `convenient means of preventing thecathode products mixing with the electrolyte, this bag being iilled witha solution of acetic acid or a metallic acetate free from arsenic. Thehydrogen formed in the process thus passes into the atmosphere Withoutcoming in contact in its nascent state with the arsenic in theelectrolyte, which would cause the formation of metallic arsenic andarseniureted hydrogen.

The electrolyte is agitated during this process. The process ispractically continuous. The paris-green is filtered or settled out ofthe solution, and from time to time fresh arsenious oxid and acetic acidor metallic acetate is added to the solution. The cathodebag is emptiedperiodically, as necessitated by the accumulation of products therein,and lled with fresh acetic acid or metallic acetate solution. Thecathode products in the Serial No. 72,348. (No specimens.)

vbag will in general consist of hydrogen gas and the hydrate of themetal contained in the acetate used. Thus if acetate of lime is used inthe electrolyte the cathode product is hydrate of lime.

In the accompanying drawing I have shown in diagrammatic verticalsection a simple apparatus for carrying out .my process, in Which- A isthe cell; ct, the copper-plate anode; b, the copper cathode inclosed inthe bag c, and CZ the electrolyte. A mechanical stirrer e is shown,actuated by the shaft f. Of course hand agitation may be used.

My invention provides a very economical and convenient electrolyticmethod of prod ucing paris-green having many advantages over theelectrolytic processes now in use, of which the following are especiallyimportant. The paris-green is produced directly. Acetate of lime may beused as the raW material, which is very cheap. Of course economy of myprocess over chemical processes is secured by the use of metallic copperinstead of sulfate of copper and the avoidance of the use of soda. Theproduction of the dangerous arsenic or arseniureted hydrogen is avoided.

l. The process of makingparis-green,which consists in electrolyzing witha copper anode a solution of an acetate and arsenious oxid.

2; The process of making paris-green,which consists in passing anelectric current through a solution of an acetate and arsenious oxidwith a copper anode and with the cathode immersed in asolution ofacetate and inclosed to prevent the cathode products mixingvwith thearsenious oXid of the electrolyte.

In testimony whereof I have hereunto set my hand in the presence oftwosubscribing Witnesses. j

RICHARD FRANCHOT.

Witnessest WILLIAM H. RAY,

II. W. KELLOGG.

